As far as I know, there are lead free products on the market since some years (far east); they do not seem to have problems with the tin pest. Why? Warm climate? Using Sb in the tin? Or is the tin pest just a theoretical problem? (Do you wonder why they bundled electronic recycling and lead free together? It seems they expect short lifetime of electronics.)
M. On Mon, Jan 16, 2006 at 02:43:51AM -0500, John Barnes wrote: > Piotr, > The information on tin pest (tin plague, tin leprosy, tin disease) is > still rather sketchy, although it has been known since the late 1800's. > In my now-347-page Bibliography for Designing Lead-Free, RoHS- > Compliant, and WEEE-Compliant Electronics (I had to add a 10th > file-cabinet drawer for my reference collection this weekend), at > http://www.dbicorporation.com/rohsbib.htm > I think I have fewer than 20 books, papers, reports, magazine articles, > and web pages that discuss tin pest. > > The earliest references that I have personally found to tin pest are: > * Louis, Henry, Metallurgy of Tin. New York: McGraw-Hill, 1911, pages > 1-3. > * Cohen, Ernst, "Infected tin or the "tin-pest"," Journal of the > Franklin Institute , vol. 173 no. 5, pp. 531, May 1912. > > Two papers on tin pest in lead-free solders are: > * Kariya, Yoshiharu, Gagg, Colin, and Plumbridge, William, "Tin pest in > lead-free solders," Soldering & Surface Mount Technology, vol. 13 no. > 1, pp. 39-40, 2000. > * Kariya, Yoshijaru, Williams, Naomi, Gagg, Colin, and Plumbridge, > William, "Tin Pest in Sn-0.5 wt.% Cu Lead-Free Solder," JOM, vol. > 53 no. 6, pp. 39-41, June 2001. > > >From everything that I have read, once tin pest begins, the only way to > stop it completely is to melt the material down and start all over > again... I'm still searching for information on whether tin pest will > continue at temperatures above 13 degrees C once it has started, or > whether it only progresses at temperatures below 13 degree C. > > I have seen a few documents that say that as little as 0.2-0.3% of lead > in a tin alloy will prevent tin pest. But this is well over the 0.1% > lead permitted by the first amendment to the RoHS Directive (2002/95/EC, > http://europa.eu.int/eur-lex/pri/en/oj/dat/2003/l_037/ > l_03720030213en00190023.pdf > > http://europa.eu.int/eur-lex/lex/LexUriServ/site/en/oj/2005/ > l_214/l_21420050819en00650065.pdf ) > > If I was manufacturing/selling a lead-free product, I'd be extremely > reluctant to provide a warranty longer than *1 year*, because of > concerns with: > * Tin whiskers, causing short circuits. > * Tin pest (tin plague, tin leprosy, tin disease), causing opens when > the solder turns to dust at temperatures below 13 degrees C. > * Sensitivity to physical shock, causing opens when a product is > dropped even a short distance onto a hard surface. > * Kirkendall voids, causing opens. > * Conductive anodic filaments (CAF), causing shorts *inside* printed > circuit boards. > > I've been recommending to our clients that they not make a whole-hog > commitment switching their products to lead-free/RoHS-compliance, if > they don't have to. If they have lead-containing products that are in > production, and can remain in production for some time without parts/ > processes going obsolete on them, consider leaving them among their > product offerings. Then, if as I fear, many lead-free products turn out > to be unsafe-- killing and injuring people, burning down buildings, > etc.-- in addition to being short-lived and unreliable, the company will > still have products that it can sell in most of the world. And maybe it > won't go bankrupt, while the companies that switched all their products > to lead-free find that they can't sell any of their products anywhere in > the world... > > If it is any consolation, the (European) Product Liability Directive ( > Directive 85/374/EEC, > http://europa.eu.int/eur-lex/en/consleg/pdf/1985/en_1985L0374_do_001.pdf > ) says in Article 7: > "The producer shall not be liable as a result of this Directive if > he proves: > ... > (d) that the defect is due to compliance of the product with > mandatory regulations issued by the public authorities; ..." > > At the personal level, when it is your own money you are spending, since > April 2005 I have been recommending to friends and co-workers: > 1. Don't buy any *new* electronics between January 2006 and June 2007. > 2. If given a choice between a RoHS-Compliant product and one that > doesn't claim RoHS-compliance, buy the latter. > 3. If offered an extended warranty, buy the longest one available... > and hope that the company offering it stays in business long > enough to replace your unit when it dies within the warranty period. > 4. If you are replacing a working unit, and have the space and can > afford it, KEEP YOUR OLD UNIT SO THAT YOU STILL HAVE SOMETHING > TO USE WHEN THE RoHS-COMPLIANT UNIT DIES. > > John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, SM IEEE > dBi Corporation > http://www.dbicorporation.com/ > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to [email protected] > > Instructions: http://listserv.ieee.org/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Scott Douglas [email protected] > Mike Cantwell [email protected] > > For policy questions, send mail to: > > Jim Bacher: [email protected] > David Heald: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc Matthias - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
